John Rumm wrote:
On 15/12/2013 11:52, Geoff Pearson wrote:

"harryagain" wrote in message
...

"Geoff Pearson" wrote in message
...
I am rebuilding a bathroom next year and beginning to scope it out.
These days finding taps that run on low pressure is quite difficult
so I am thinking of replacing the hot water cylinder with one that
would take high pressure and taking out the tank in the roof space.
I presume it would still be heated indirectly from the boiler which
is 1.5 storeys below. That would also solve a problem in the kitchen
where the cold is on the mains and the hot is on low pressure. At
one time mixer taps were available where this worked (eg KWC) - have
they all gone now?

In the bathroom if this is too difficult/expensive I might keep the
Ideal Standard brassware - only 27 years old and working perfectly
still.

Any pitfalls here?


You would be better to keep what you've got.
There are no advantages to changing over unless you like high pressure
showers.

As usual harry is, at best, over simplifying. There can be plenty of
advantages when a system is installed in appropriate circumstances.

If your incoming mains water pipe is crudded up, you may well find it
takes forever to fill the bath with a mains pressure hot water tank.

Alternatively you may find with a decent main supply that bath fills become much faster...

Also you would have moving parts that need to be maintained.


I am gently coming to that conclusion. The water main is fine - the
water pressure is huge - and we have soft water so it does not crud up
and was renewed in plastic in 1987 (with a big grant from the Council).

In one sense then you have the ideal setup for mains pressure hot water,
so it really depends on how well the existing system performs, and what
you are attempting to achieve.

In my case there was no contest, the gravity fed system I had previously
was hopeless and completely unsuited to the property. What I have now has
has proved to be the best hot water system I have ever used, and
outclasses the previous in every respect. However that is not going to be
the same for everyone.



I've often wondered if there is a good way to safely and legally boost an
existing HW tank to work much nearer its rated maximum pressure. Most
vented tanks I think are rated to at least 1bar and that would give a
useful boost to most systems if you could get the header tank high enough
(which in most cases of course you never can - flats excepted).

I guess the problem is providing a fail safe pressure relief system.

Tim